Epoxidation of cyclohexene with O2 over the composite catalysts of Mn-montmorillonite coordinated with novel Schiff-base ligands

Abstract

The catalytic activity of the heterogeneous catalysts of Mn-mont (where mont represents montmorillonite) coordinated with Schiff-base ligands for epoxidation of cyclohexene by O₂ under Mukaiyama conditions was studied. The catalysts were characterized by IR, UV-vis DRS, XRD, SEM and ICP. The heterogeneous catalysts were proved to promote the epoxidation of cyclohexene efficiently, the effects of various reaction conditions on the catalytic reaction were optimized and obtained as high as 100% conversion with 90.0% selectivity of epoxycyclohexane at 40 °C in 5 h with molecular oxygen as oxidant in acetonitrile. Repeated runs indicated that the catalysts were stable for at least 3 cycles. Thus, the heterogeneous catalysts of Mn-mont coordinated with Schiff-base ligands were proved to be environmentally friendly and economical for the epoxidation of cyclohexene.